Three-dimensional laser beam machine

ABSTRACT

In a three-dimensional laser beam machine having a head structure in which a processing point is not moved when a rotation axis and an attitude axis are rotated, the machine has: means for storing information of current angles of the rotation axis and the attitude axis, and calculating a nozzle direction vector from the angles; means for, based on the nozzle direction vector, determining angles of a nozzle in a vertical direction and a horizontal direction consisting of a Z-axis of an orthogonal coordinate system; and means for displaying the determined nozzle angles.

TECHNICAL FIELD

The present invention relates to a control apparatus for athree-dimensional laser beam machine having a head structure in whichthe processing point is not moved when the rotation axis and theattitude axis are rotated, the control apparatus having a function of,based on a nozzle direction vector, displaying an angle of a nozzle in avertical direction consisting of the Z-axis of an orthogonal coordinatesystem, and an angle in a horizontal direction when the nozzle directionvector is projected to the XY-plane.

BACKGROUND ART

Hereinafter, the configuration of a three-dimensional laser beam machinethat machines a planar or three-dimensional workpiece shape, and thathas a structure of a head in which the processing point is not movedwhen the rotation axis and the attitude axis are rotated (hereinafter,such a head is referred to as unidirectional head) will be describedwith reference to FIGS. 6, 7, and 8.

FIG. 6 is a perspective view showing the configurations of axes of athree-dimensional laser beam machine on which a unidirectional head ismounted, FIGS. 7A and 7B are enlarged views of a processing head of thethree-dimensional laser beam machine on which a unidirectional head ismounted, and FIG. 8 is a block diagram showing the configuration of thethree-dimensional laser beam machine.

In the figures, 109 denotes an attitude axis (hereinafter, referred toas U-axis) which is positioned at the drive end of an arm 111, 110denotes a rotation shaft (hereinafter, referred to as W-axis) which isconnected to the U-axis 109, and 108 denotes a Z-axis which is connectedto the W-axis 110. These axes constitute the arm 111.

The processing head 3 has: the W-axis 110 which is placed at the tip endof a Z-axis bearing 115, and which can be rotated in a direction of anarrow +α or −α about the Z-axis by a rotary bearing 114; and the U-axis109 which is attached to the tip end of the W-axis 110 by an attitudebearing 113, and which can be rotated in a direction of an arrow +β or−β about an axis that is inclined by 45 degrees with respect to theZ-axis. A processing nozzle 4 is attached to the tip end of the U-axis109. Since the U-axis 109 is rotated about the axis which is inclined by45 degrees with respect to the horizontal plane, the angle of the U-axisdoes not correspond in a one-to-one relationship to the vertical angleat which the processing nozzle 4 is directed.

The reference numeral 113 denotes the attitude bearing which rotates theU-axis 109 by a servo motor SM5 in the direction of the arrow +β or −β,and 114 denotes the rotary bearing which rotates the W-axis 110 by aservo motor SM4 in the direction of the arrow +α or −α.

The reference numeral 115 denotes the Z-axis bearing which moves theprocessing head 3 by a servo motor SM3 in the direction of an arrow Z,116 denotes a Y-axis bearing which moves the processing head 3 by aservo motor SM2 in the direction of an arrow Y, and 117 denotes anX-axis bearing which moves a processing table 2 by a servo motor SM1 inthe direction of an arrow X. The servo motors SM1 to SM5 are driven by adriving signal from an NC controller 8. The reference letter P denotes aprocessing point the position of which is not moved even when the W-axis110 and the U-axis 109 are rotated.

The reference numeral 105 denotes a laser oscillator which generates alaser beam, and 103 denotes an operation section through which the NCcontroller is operated.

When laser beam processing is to be conducted by using the thusconfigured laser beam machine, it is requested in laser beam processingwhich machines a planar or three-dimensional workpiece shape that thedirection and posture of the processing nozzle 4 are alwaysperpendicular to the processing plane in order to maintain the opticalaxis of the laser beam irradiating the processing plane to be normal tothe processing plane. Before conducting processing, therefore, theoperator makes the processing point P coincident with a point(hereinafter, referred to as teaching point) on a processing line K of aprocessing workpiece 9, and in advance of actual processing conducts ateaching work in which a teaching point satisfying the requirement isinput as a teaching data into a program.

During laser beam processing, in accordance with the teaching data, thespot of the laser beam is controlled so as to advance along theprocessing line K while maintaining the distance of the processing head3 with respect to the processing workpiece 9 to be constant.

FIG. 9 is a view showing angles of horizontal and vertical components ofa unit vector (hereinafter, referred to as nozzle direction vector) in adirection indicated by the processing nozzle 4 from the angles of theW-axis 110 and the U-axis 109, in a coordinate system (hereinafter,referred to as orthogonal coordinate system) in which the XY plane isdefined as a horizontal plane and X-, Y-, and Z-axes are outer productsof the other axes or relationships of Y×Z, Z×X, and X×Y are established.The reference numeral 70 denotes a teaching point in an inclined portionof a workpiece, and 71 denotes a line segment formed by the origin O andthe teaching point 70, i.e., the nozzle direction vector.

The reference numeral 72 denotes a point which is obtained by projectingthe teaching point 70 onto the XY-plane, 73 denotes a line segment whichis obtained by projecting the line segment 71 onto the XY-plane, i.e., aline segment which is formed by the origin O and the point 72, 74denotes the X component dx at the processing point 70, 75 denotes the Ycomponent dy at the processing point 70, 76 denotes the Z component dzat the processing point 70, θ denotes an angle θ of the verticalcomponent formed by the line segment 71 and the Z-axis, and φ denotes anangle φ of the horizontal component formed by the line segment 73 andthe X-axis. In FIG. 9, because of the structure of the processing head3, it is known that the nozzle direction vector d is given from theangle α of the W-axis 110 and the angle β of the U-axis 109 as:$d = {\begin{pmatrix}{dx} \\{dy} \\{dz}\end{pmatrix} = \begin{pmatrix}{{{\frac{1}{2} \cdot \cos}\quad \alpha} - {{\frac{1}{2} \cdot \cos}\quad {\alpha \cdot \cos}\quad \beta} + {{\frac{\sqrt{2}}{2} \cdot \sin}\quad {\alpha \cdot \sin}\quad \beta}} \\{{{{{- \frac{1}{2}} \cdot \sin}\quad \alpha} + {{\frac{1}{2} \cdot \sin}\quad {\alpha \cdot \cos}\quad \beta} + {{\frac{\sqrt{2}}{2} \cdot \cos}\quad {\alpha \cdot \sin}\quad \beta}}~} \\{\frac{1}{2} + {{\frac{1}{2} \cdot \cos}\quad \beta}} \\\quad\end{pmatrix}}$

When a polar coordinate system is used, the relationships between thecomponents dx, dy, and dz at the teaching point 70 in FIG. 9 and theangles of the horizontal component and the vertical component areobtained by the following expressions:

cos θ=dz

tan φ=dy/dx

From the expressions, the angles in the horizontal and verticaldirections are obtained.

θ=a cos(dz)

φ=a tan(dy/dx)

As described above, the conversion expressions contain an inversetrigonometric function. In the case where only the angle β of the U-axis109 is known, it is impossible to read the angle θ of the verticalcomponent by which the processing nozzle 4 is directed.

The above is similarly applicable to the relationship between the W-axis110 and the angle φ of the horizontal component.

FIGS. 10A and 10B are views showing an attitude change of the processinghead in a teaching process, and processing in which the incident angleof the laser beam is inclined, FIG. 10A shows an attitude change of theprocessing head in a teaching process and in an attitude change cornerportion in a three-dimensional laser beam machine having a headstructure in which the processing point is not moved when the W-axis andthe U-axis are rotated, and FIG. 10B is a view showing processing(hereinafter, referred to as taper processing) in which the incidentangle of the laser beam is inclined with respect to the surface of theworkpiece.

In the figure, P1 denotes a teaching point which is on the processingline K of the processing workpiece 9 and on a horizontal plane, P2denotes a teaching point which is on the processing line K of theprocessing workpiece 9 and on a 45-degree inclined plane, P3 denotes ateaching point which is on the processing line K of the processingworkpiece 9 and on an uprighting plane, 3 a and 4 a denote a processinghead and a processing nozzle which are downward directed at the teachingpoint P1, 3 b and 4 b denote a processing head and a processing nozzlewhich are directed to 45 degrees at the teaching point P2, and 3 c and 4c denote a processing head and a processing nozzle which arehorizontally directed at the teaching point P3.

When teaching is to be conducted, the operator reads the shape of acompleted workpiece from a predetermined drawing for conducting laserbeam processing. Based on the shape, the operator then scribes theprocessing line K on a workpiece for producing teaching data, anddetermines the nozzle angle at each of the teaching points on theprocessing line K. When a perpendicular state is to be then establishedat each of the teaching points P1, P2, and P3 on the processingworkpiece 9, the nozzle angles are adjusted to 0°, 45°, and 90° whichare workpiece inclination angles determined from the drawing.

In FIG. 10B, A denotes a designated angle in the taper processing, andthe nozzle angles are requested to be adjusted to this value.

The operator cannot calculate correct values of the W- and U-axes fromthe nozzle angles which are determined from the drawing. Therefore, itis difficult to attain numerical coincidence, and approximate valuesonly can be estimated at the best.

FIG. 11 is a view showing a conventional coordinate display screen thatdisplays coordinates of axes in a machine coordinate system in which acharacteristic position defined by a machine is used as the origin. Thescreen is displayed during a teaching work.

In the screen, the position (hereinafter, referred to as tip endposition) of the processing point P which is at the tip end of theprocessing nozzle 4 on the X-, Y-, and Z-axes is shown with respect tothe machine origin peculiar to the machine, and the attitude of theprocessing nozzle 4 is indicated by means of the angles α and β of theW- and U-axes.

When the X-, Y-, Z-, W-, and U-axes are further moved, the values of theaxes on the screen are updated on occasion in accordance with themovement.

Since a teaching data is produced by using the coordinates, the valuesof the W- and U-axes are necessary in processing to control the spot ofthe laser beam to advance along the processing line K by means ofprocessing in the NC.

However, there are few situations where such values are handled asinformation to be indicated to the operator.

FIG. 12 shows a flowchart of a conventional teaching work in an inclinedportion of a workpiece or taper processing.

As preparations for a teaching work in which a three-dimensional programis prepared by teaching of processing points, various items such aseffectiveness of the use of a teaching box (hereinafter, abbreviated toT/B) 7 are set, and commands such as shutter opening of auxiliaryfunction codes which are default settings in a processing program areset in step ST11.

While seeing the coordinates of the X-, Y-, and Z-axes on the coordinatedisplay screen shown in FIG. 11, thereafter, the tip end position ismoved in step ST12 to a teaching point by using a processing shaft feedkey disposed on the T/B 7, or a handle and a joy stick.

At this time, if the angles of the processing nozzle 4 must be adjustedby teaching in an inclined portion of a workpiece or taper processing(step ST13), the W-axis 110 and the U-axis 109 are manually rotated instep ST14 in order to set the attitude of the processing nozzle 4.

In step ST15, step ST14 is repeated until it is affirmed as a result ofchecking of the nozzle angles by visual inspection that theperpendicular state is realized or the angles in the taper processingare attained.

After the setting of the tip end position and the attitude at theteaching point is ended in step ST15, teaching is conducted as teachingdata in step ST16.

Subsequently to the above, while seeing the coordinate display shown inFIG. 11, the tip end position is similarly moved to the next teachingpoint by using the processing shaft feed key disposed on the T/B 7, orthe handle and the joy stick, and teaching points of the processingprogram are produced by the teaching work.

In the case of a teaching work in which the angles of the processingnozzle 4 are not adjusted in step ST13, the works of steps ST14 and ST15are omitted.

Finally, commands such as shutter closing and program end of auxiliaryfunction codes are input in step ST18, and the preparation of theprocessing program is ended.

In a teaching work in a three-dimensional laser beam machine having thehead structure of FIGS. 7A and 7B, conventionally, the method of theflowchart shown in FIG. 12 is established as a standard operation.

Because of visual checking, however, the accuracy of the adjustment ofthe nozzle angles in the perpendicular state and the taper processing isso poor that satisfactory processing is hardly realized. Moreover, theteaching work requires a long time period.

In the work of checking the position and attitude of each teaching pointimmediately before processing, when the angles of the W-axis 110 and theU-axis 109 are to be changed, it is necessary to readjust the attitudeat the teaching point, and the attitude is corrected on the basis of theoperations of steps ST13 to ST16 of the above-mentioned flowchart.

For the purpose of reference, the configuration of a three-dimensionallaser beam machine having a structure of another kind of head type(hereinafter, referred to as offset type head) which is provided with aslim processing head, and which is suitable for processing of a deepdrawing workpiece will be described with reference to FIGS. 13 and 14.

FIG. 13 is a perspective view showing the configurations of axes of athree-dimensional laser beam machine on which an offset type head ismounted, and FIGS. 14A and 14B are enlarged views of a processing headof the three-dimensional laser beam machine on which an offset type headis mounted. The components denoted by the same reference numerals asthose of the three-dimensional laser beam machine on which theunidirectional head shown in FIGS. 7A and 7B is mounted are structuredin a substantially same manner, and the portion of the arm 111 isdifferently configured.

Referring to the figures, the processing head 4 has: a rotation axis(hereinafter, referred to as C-axis) 122 which is placed at the tip endof the Z-axis member 115, and which can be rotated in a direction of anarrow +α′ or −α′ about the Z-axis by the rotary bearing 114; and anattitude axis (hereinafter, referred to as A-axis) 121 which is attachedto the tip end of the C-axis 122 by the attitude bearing 113, and whichcan be rotated in a direction of an arrow +β′ or −α′ about an axis (theC-axis 122) that is perpendicular to the Z-axis. The processing nozzle 4is attached to the tip end of the A-axis 121.

The angle of the A-axis 121 corresponds in a one-to-one relationship tothe vertical angle of the processing nozzle 4, and that of the C-axis122 corresponds in a one-to-one relationship to the horizontal angle ofthe processing nozzle 4.

Next, also with respect to the offset type head, relationships betweenthe angles of the rotation axis and the attitude axis, and the angles ofthe horizontal component and the vertical component of the nozzledirection vector are shown.

In FIG. 14B, because of the structure of the processing head 3, it isknown that the nozzle direction vector d′ is given from the angle α′ ofthe C-axis 122 and the angle β′ of the A-axis 121 as:$d^{\prime} = {\begin{pmatrix}{dx} \\{dy} \\{dz}\end{pmatrix} = \begin{pmatrix}{\sin \quad {\alpha^{\prime} \cdot \sin}\quad \beta^{\prime}} \\{\cos \quad {\alpha^{\prime} \cdot \sin}\quad \beta^{\prime}} \\{\cos \quad \beta^{\prime}}\end{pmatrix}}$

When a polar coordinate system is used, the relationships between thecomponents dx, dy, and dz at the teaching point 70 in FIG. 9 and theangles of the horizontal component and the vertical component areobtained by the following expressions:

cos θ=dz

tan φ=dy/dx

From the expressions, the angles of the horizontal component and thevertical component are obtained.

θ=β′

φ=90°−α′

Even when only the angle β′ of the A-axis 121 is known, it is possibleto read the angle θ of the vertical component by which the processingnozzle 4 is directed.

The above is similarly applicable to the relationship between the C-axis122 and the angle φ of the horizontal component.

FIG. 15 shows a flowchart of a teaching work in the three-dimensionallaser beam machine having an offset type head.

Referring to the figure, operations of the steps up to step ST22 areidentical with those of the steps up to step ST12 of the unidirectionalhead shown in FIG. 12. Thereafter, in the case where the angles of theprocessing nozzle 4 are required to be adjusted (step ST23), a tip endfixing mode in which tip end position is fixed and the C-axis 122 andthe A-axis 121 are rotated to match the attitude is set in step ST24.

While seeing the display of the angles the C-axis 122 and the A-axis 121on the coordinate display screen, the C-axis 122 and the A-axis 121 arerotated in step ST25 until a perpendicular state is attained in a knowninclined portion of a workpiece such as shown in FIG. 14A, or theprocessing nozzle 4 is set to the angle for the taper processing.

After the setting of the tip end position and the attitude at theteaching point is ended, teaching is conducted as teaching data in stepST26.

Operations of subsequent steps ST27 and ST28 are identical with those ofsteps ST17 and ST18 of the unidirectional head shown in FIG. 12.

In the teaching work in the three-dimensional laser beam machine havingthe conventional head structure shown in FIG. 13, the shape of acompleted workpiece is read from a drawing and the nozzle angles arethen determined as shown in the above-mentioned flowchart. Since thenozzle angles correspond in a one-to-one relationship to the C-axis andthe A-axis, adjustment to a perpendicular state and the angle designatedin the drawing can be conducted easily and accurately on the knowninclined portion of the workpiece, so that also the time period of theteaching work can be shortened.

As shown in the flowchart of FIG. 15, the teaching work in athree-dimensional laser beam machine having the conventional offset typehead structure is easily conducted. However, the teaching work in aninclined portion of a workpiece or taper processing using athree-dimensional laser beam machine having the unidirectional headstructure has a problem in that the accuracy of the nozzle angle at ateaching point in an inclined portion of a workpiece or taper processingis low because the W-axis and the U-axis are manually rotated until theperpendicular state is realized or the angle in the taper processing isattained, while the operator visually checks the nozzle angles inteaching, and also a further problem in that, as the number of teachingpoints is more increased, teaching requires a longer time period becauseteaching is conducted on each of teaching points.

In the teaching work in a three-dimensional laser beam machine having ahead structure in which the processing point is not moved when theW-axis and the U-axis are rotated, the actual angles of the processingnozzle in the horizontal and vertical directions cannot be known fromthe angles of the W-axis and the U-axis as described in the prior artparagraph. For the user who previously had a three-dimensional laserbeam machine on which an offset type head is mounted, therefore, such ateaching work is poor in easiness of the nozzle angle adjustment and lowin working efficiency as compared with that in the case of an offsettype head.

DISCLOSURE OF THE INVENTION

The invention has been conducted in order to solve the problems. It isan object of the invention to improve the efficiency of a teaching workin a three-dimensional laser beam machine having a head structure inwhich the processing point is not moved when the W-axis and the U-axisare rotated, by calculating and displaying the angles of a nozzle in thehorizontal and vertical directions in an orthogonal coordinate system.

It is another object of the invention to provide a control apparatus fora three-dimensional laser beam machine which can easily establish aperpendicular state for a processing workpiece in which the inclinationangle is known.

In order to attain the objects, according to a first aspect, in athree-dimensional laser beam machine having a head structure in which aprocessing point is not moved when a rotation axis and an attitude axisare rotated, the machine comprises: means for storing information ofcurrent angles of the rotation axis and the attitude axis, andcalculating a nozzle direction vector from the angles; means for, basedon the nozzle direction vector, determining angles of a nozzle in avertical direction and a horizontal direction consisting of a Z-axis ofan orthogonal coordinate system; and means for displaying the determinednozzle angles.

Furthermore, determination of the angles of the nozzle in the verticaldirection and the horizontal direction is obtained on the basis of thenozzle direction vector from the angle of the nozzle in the verticaldirection consisting of the Z-axis of the orthogonal coordinate system,and an angle in the horizontal direction consisting of an X-axis whenthe nozzle direction vector is projected onto an XY-plane.

The machine further comprises nozzle angle setting means for previouslystoring angles of the nozzle, and comprises notifying means forcomparing with the determined angles of the nozzle in the verticaldirection and the horizontal direction, to notify that the previouslystored nozzle angles are attained.

Furthermore, the nozzle angles are displayed on a remote operationsection such as a teaching box.

The machine further comprises nozzle angle setting means for previouslystoring angles of the nozzle, and compares with the determined angles ofthe nozzle in the vertical direction and the horizontal direction,whereby the rotation axis and the attitude axis of the nozzle arerotated and the nozzle is positioned to the previously stored nozzleangles.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a whole configuration diagram showing functions of thethree-dimensional laser beam machine of the invention, and the flow ofthe process.

FIG. 2 is a view showing angles of a nozzle in the horizontal andvertical directions as seen from an orthogonal coordinate system.

FIG. 3 is a structure diagram showing the structure of a processinghead.

FIG. 4 is a view of a coordinate display screen containing nozzle anglesaccording to the invention, and a screen setting view in a firstembodiment.

FIG. 5 is a flowchart of a teaching work according to the invention.

FIG. 6 is a perspective view showing the configurations of axes of athree-dimensional laser beam machine on which a unidirectional head ismounted.

FIGS. 7A and 7B are enlarged views of a processing head of thethree-dimensional laser beam machine on which a unidirectional head ismounted.

FIG. 8 is a block diagram showing the configuration of the conventionalthree-dimensional laser beam machine.

FIG. 9 is a view showing angles of a nozzle in the horizontal andvertical directions as seen from an orthogonal coordinate system.

FIGS. 10A and 10B are views schematically showing an attitude change ofa processing head and processing.

FIG. 11 is a view showing a conventional coordinate display screen.

FIG. 12 is a flowchart of a teaching work of a conventionalunidirectional head.

FIG. 13 is a perspective view showing the configurations of axes of athree-dimensional laser beam machine on which an offset type head ismounted.

FIGS. 14A and 14B are enlarged views of a processing head of thethree-dimensional laser beam machine on which an offset type head ismounted.

FIG. 15 is a flowchart of a teaching work of an offset type head.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1.

FIG. 1 is a perspective view of a system of a three-dimensional laserbeam machine on which a unidirectional head is mounted, in a teachingwork.

In the figure, 1 denotes the body of a three-dimensional machine, 2denotes a processing table which is disposed on a bed so as to bemovable in the X-axis direction, 3 denotes a processing head which isattached to a Z-axis unit 5, 4 denotes a processing nozzle which isattached to the tip end of the processing head 3, and 5 denotes theZ-axis unit which can move the processing head 3 in the direction of anarrow Z, and which is disposed on a Y-axis unit 6 so as to be movable inthe Z-axis direction.

The reference numeral 6 denotes the Y-axis unit which can move theZ-axis unit 5 in the direction of an arrow Y, and which is movablydisposed on a cross rail that is horizontally laid between right andleft columns.

The reference numeral 7 denotes a pendant type teaching box, 8 denotesan NC controller which is configured by a computer, and which has acontrol panel 8 a serving as a man-machine interface, and a screendisplaying section 8 b configured by a CRT, a liquid crystal, or thelike, and 9 denotes a processing workpiece which is placed on theprocessing table 2.

The workpiece table 2, the Z-axis unit 5, and the Y-axis unit 6 aredriven by an X-axis servo motor, a Z-axis servo motor, and a Y-axisservo motor which are not shown, respectively, and positionallycontrolled by axis commands from the NC controller 8. The referencenumeral 10 denotes a nozzle direction storing section which calculatesand stores a unit vector (hereinafter, referred to as nozzle directionvector) in a direction indicated by the processing nozzle 4 from thecurrent angles of the W-axis 22 and the U-axis 24, 11 denotes a nozzleangle calculating section which, on the basis of the nozzle directionvector calculated by the nozzle direction storing section 10, calculatesthe angle of the nozzle in the vertical direction consisting of theZ-axis of the orthogonal coordinate system, and the angle in thehorizontal direction when the nozzle direction vector is projected ontothe XY-plane, 12 denotes a nozzle angle setting and storing sectionwhich stores a set value of a nozzle angle which is set on the screen ofthe screen displaying section 8 b or the T/B 7, and which is to bepreviously moved, 13 denotes a nozzle angle comparing and judgingsection which judges whether the nozzle angle setting and storingsection 12 coincides with a result of the nozzle angle calculatingsection 11 or not, and which, if the coincidence is attained, turns onan arrival signal, and 14 denotes a nozzle angle displaying sectionwhich displays the angles in the horizontal and vertical directionscalculated by the nozzle angle calculating section 11, on the T/B 7 andthe screen displaying section 8 b of the NC controller 8, and which,when the arrival signal of the nozzle angle comparing and judgingsection 13 is on, displays a mark in the vicinity of the nozzle angle.

The nozzle direction storing section 10, the nozzle angle calculatingsection 11, the nozzle angle setting and storing section 12, the nozzleangle comparing and judging section 13, and the nozzle angle displayingsection 14 are internal processing functions of the NC controller 8.

In the calculation process of the nozzle angle calculating section 11,calculation is implemented by the following logical expression.

FIG. 2 is a view showing angles of the nozzle direction vector in thehorizontal and vertical directions in a orthogonal coordinate system inwhich the XY plane is defined as a horizontal plane and X-, Y-, andZ-axes are outer products of the other axes or relationships of Y×Z,Z×X, and X×Y are established.

The reference numeral 15 denotes a teaching point in an inclined portionof a workpiece, 16 denotes a line segment formed by the origin O and theteaching point 15, i.e., the nozzle direction vector, 17 denotes a pointwhich is obtained by projecting the teaching point 15 onto the XY-plane,18 denotes a line segment which is obtained by projecting the linesegment 16 onto the XY-plane, i.e., a line segment formed by the originand the point 17, 19 denotes the X component dx at the processing point15, 20 denotes the Y component dy at the processing point 15, 21 denotesthe Z component dz at the processing point 15, θ denotes an angle θ ofthe vertical component formed by the line segment 14 and the Z-axis, andφ denotes an angle φ of the horizontal component formed by the linesegment 16 and the X-axis.

In FIG. 2, because of the structure of the processing head 3, it isknown that the nozzle direction vector d is given from the angles α andβ of the W-axis 22 and the U-axis 24 as: $d = {\begin{pmatrix}{dx} \\{dy} \\{dz}\end{pmatrix} = \begin{pmatrix}{{{\frac{1}{2} \cdot \cos}\quad \alpha} - {{\frac{1}{2} \cdot \cos}\quad {\alpha \cdot \cos}\quad \beta} + {{\frac{\sqrt{2}}{2} \cdot \sin}\quad {\alpha \cdot \sin}\quad \beta}} \\{{{{- \frac{1}{2}} \cdot \sin}\quad \alpha} + {{\frac{1}{2} \cdot \sin}\quad {\alpha \cdot \cos}\quad \beta} + {{\frac{\sqrt{2}}{2} \cdot \cos}\quad {\alpha \cdot \sin}\quad \beta}} \\{\frac{1}{2} + {{\frac{1}{2} \cdot \cos}\quad \beta}}\end{pmatrix}}$

When a polar coordinate system is used, the relationships between thecomponents dx, dy, and dz at the teaching point 15 in FIG. 2 and theangles of the horizontal component and the vertical component areobtained by the following expressions:

cos θ=dz

tan φ=dy/dx

From the expressions, the angles in the horizontal and verticaldirections are obtained.

θ=a cos(dz)

φ=a tan(dy/dx)

In the angle φ in the horizontal direction, however, conditionclassification is must be conducted in the following manner:

dx>0: φ=a tan(dy/dx)

dx<0,dy>0: φ=a tan(dy/dx)+180°

dx<0,dy<0: φ=a tan(dy/dx)−180°

Furthermore, θ′ is an angle in the vertical direction with respect tothe XY-plane, and obtained as follows:

θ′=90°−θ

Therefore, the angles in the horizontal and vertical directions arederived from the angles α and β of the W-axis 22 and the U-axis 24 byusing the above relational expressions.

Moreover, the processing head 3 is configured in a similar manner asthat of the conventional art. As shown in FIG. 3, the processing headhas: a rotation axis (hereinafter, referred to as W-axis) 22 which isattached to the tip end of the Z-axis unit 5, and which can be rotatedin a direction of an arrow +α or −α about the Z-axis by a bearing member27; and an attitude axis (hereinafter, referred to as U-axis) 24 whichis attached to the tip end of the W-axis 22 by a bearing member 23, andwhich can be rotated in a direction of an arrow +β or −β about an axisthat is inclined by 45 degrees with respect to the Z-axis. Theprocessing nozzle 4 is attached to the tip end of the U-axis 24.

The W-axis 22 is rotated by a W-axis servo motor 25, and the U-axis 24is rotated by a U-axis servo motor 26.

The X-axis servo motor, the Y-axis servo motor, and the Z-axis servomotor (not shown), and the W-axis servo motor 25 and the U-axis servomotor 26 are driven by a driving signal from the NC controller 8, andcontrolled so that, while maintaining the distance of the processingnozzle 4 with respect to the workpiece on the processing table 2 to beconstant, the spot of the laser beam follows the processing line inaccordance with the teaching data, and the nozzle angle of theprocessing nozzle 4 is substantially perpendicular (in the direction ofthe normal line) to the surface of the processing workpiece 9.

FIG. 4 is a view showing the screen of a coordinate display containing adisplay of nozzle angles.

In the nozzle angles, angles in the horizontal and vertical directionsas seen from an orthogonal coordinate system are displayed.

In accordance with the rotation of the W-axis 22 and the U-axis 24, alsothe display of the nozzle angles is varied by correspondingly conductingthe above-mentioned calculation.

In the case where nozzle angles which are to be previously moved are seton the screen of the screen displaying section 8 b or the T/B 7, when abutton on the control panel 8 a or the T/B 7 is pressed, the W-axis 22and the U-axis 24 are rotated until the nozzle angle comparing andjudging section 13 judges that the values calculated by the nozzle anglecalculating section 11 coincide with the preset values.

If the nozzle angle comparing and judging section 13 judges that thenozzle angles reach the preset values, the W-axis 22 and the U-axis 24are stopped, and a mark of # is displayed at the side of the nozzleangle display, by the nozzle angle displaying section 34.

FIG. 5 is a flowchart of a teaching work in an inclined portion of aworkpiece or taper processing.

As preparations for a teaching work in which a three-dimensional programis prepared by teaching of processing points, various items such aseffectiveness of the use of the T/B 7 are set, and commands such asshutter opening of auxiliary function codes which are default settingsin a processing program are then set in step ST1.

While seeing the coordinates of the X-, Y-, and Z-axes on the coordinatedisplay screen shown in FIG. 4, thereafter, the tip end position ismoved in step ST2 to a teaching point by using a processing shaft feedkey disposed on the T/B 7, or a handle and a joy stick. At this time, ifthe angles of the processing nozzle 4 must be adjusted by teaching in aninclined portion of a workpiece or taper processing (step ST3), theU-axis 24 and the W-axis 22 are rotated in step ST14 while checking thenozzle angles shown in FIG. 4 and displayed on the T/B 7 or the screendisplaying section 8 b of the controller 8, until the perpendicularstate is realized or the angles in the taper processing are attained.

After the setting of the tip end position and the attitude at theteaching point, teaching is conducted as teaching data in step ST5.

Thereafter, while seeing the coordinate display shown in FIG. 4, the tipend position is similarly moved in step ST6 to the next teaching pointby using the processing shaft feed key disposed on the T/B 7, or thehandle and the joy stick, and teaching points of the processing programare produced by the teaching work.

In the case of a teaching work in which the nozzle angles are notadjusted in an inclined portion of a workpiece or taper processing, thework of step ST4 is omitted.

Finally, commands such as shutter closing and program end of auxiliaryfunction codes are input in step ST7, and the preparation of theprocessing program is ended.

According to the embodiment, the nozzle angles can be displayed for aunidirectional head in which the efficiency of a teaching work is low,and hence the perpendicular state with respect to the surface of aworkpiece can be easily produced, and the work of repeatedly visuallychecking the nozzle angles can be omitted, so that the efficiency of theteaching work can be improved.

With respect to a request for taper processing, moreover, angles oftaper processing can be matched at a high accuracy.

On the other hand, for the user who previously had a three-dimensionallaser beam machine on which an offset type head is mounted, the ease ofuse is enhanced because a teaching work can be conducted while graspingthe nozzle angles, also in a unidirectional head in the same manner asan offset type head.

Furthermore, angle information in the horizontal and vertical directionscan be displayed on a remote operating apparatus such as a T/B, andhence the angles of the nozzle in the horizontal and vertical directionscan be checked on the spot during a teaching work, whereby the workingefficiency can be improved by shortening of the time period.

In the case of an inclined portion of a workpiece or where the nozzleangles are designated in a drawing, the nozzle angles can be madecoincident with the actual nozzle angles, and, with respect to aworkpiece in which the inclination angle is known, the perpendicularstate can be easily attained. Therefore, a teaching work can beconducted more efficiently.

As described above in detail, according to the invention, aperpendicular state of a nozzle with respect to the surface of aworkpiece can be easily established, so that the efficiency of ateaching work can be improved.

Since comparison between preset nozzle angles and the actual nozzleangles during a teaching work can be conducted, the working efficiencyof the operator can be improved.

Since the angles of the nozzle in the horizontal and vertical directionscan be checked on the spot during a teaching work, the workingefficiency can be improved by shortening of the time period.

INDUSTRIAL APPLICABILITY

As described above, the three-dimensional laser beam machine of theinvention is suitable for displaying the nozzle angles of a processinghead to improve the efficiency of a teaching work.

What is claimed is:
 1. A three-dimensional laser beam machine having ahead structure in which a processing point is not moved when a rotationaxis and an attitude axis are rotated, wherein said machine comprises:means for storing information of current angles of said rotation axisand said attitude axis, and calculating a nozzle direction vector fromthe angles; means for, based on the nozzle direction vector, determiningangles of a nozzle in a vertical direction and a horizontal directionconsisting of a Z-axis of an orthogonal coordinate system; and means fordisplaying the determined nozzle angles.
 2. A three-dimensional laserbeam machine according to claim 1, wherein determination of the anglesof said nozzle in the vertical direction and the horizontal direction isobtained on the basis of the nozzle direction vector from the angle ofsaid nozzle in the vertical direction consisting of the Z-axis of theorthogonal coordinate system, and an angle in the horizontal directionconsisting of an X-axis when the nozzle direction vector is projectedonto an XY-plane.
 3. A three-dimensional laser beam machine according toclaim 1 or 2, wherein said machine further comprises nozzle anglesetting means for previously storing angles of said nozzle, andcomprises notifying means for comparing with the determined angles ofsaid nozzle in the vertical direction and the horizontal direction, tonotify that the previously stored nozzle angles are attained.
 4. Athree-dimensional laser beam machine according to any one of claims 1 to3, wherein the nozzle angles are displayed on a remote operation sectionsuch as a teaching box.
 5. A three-dimensional laser beam machineaccording to any one of claims 1 to 3, wherein said machine furthercomprises nozzle angle setting means for previously storing angles ofsaid nozzle, and compares with the determined angles of the nozzle inthe vertical direction and the horizontal direction, whereby therotation axis and the attitude axis of said nozzle are rotated and saidnozzle is positioned to the previously stored nozzle angles.
 6. Athree-dimensional laser beam machine according to claim 4, wherein saidmachine further comprises nozzle angle setting means for previouslystoring angles of said nozzle, and compares with the determined anglesof the nozzle in the vertical direction and the horizontal direction,whereby the rotation axis and the attitude axis of said nozzle arerotated and said nozzle is positioned to the previously stored nozzleangles.